Various types of orthodontic brackets and appliances have been devised for mounting on a patient's teeth for relocating one or more teeth in the patient's mouth. Heretofore, such brackets were placed on the outer surface of the teeth and provided a very unsightly appearance to the patient. It also caused considerable discomfort due to the rubbing of the inside of the patient's lips against the protruding brackets. Recently, attempts have been made to mount the brackets on the rear surface or tooth lingual to eliminate the bracket from being exposed eliminating one of the main objectives to wearing such brackets or orthodontic appliances, namely the unsightly appearance. Also, mounting of the bracket on the tooth lingual eliminates the uncomfortable contact with the inside surface of the patient's lips.
However, the mounting of the brackets on the inside surface of the teeth increases the difficulty of the installation of arch wires and their subsequent attachment to the brackets due to the reduced work area and in accessability by the dentist. During the course of treatment of a patient, the arch wire is replaced many times in order to achieve the desired teeth movement. Such arch wire replacement consumes considerable time by the dentist and increases the discomfort of the patient.
Previous orthodontic brackets were formed with a horizontal channel or slot into which the arch wire was inserted and secured by tie wires or the like. The use of such horizontally opening bracket channels is unsatisfactory when the bracket is mounted on the inside surface of the tooth. Some prior brackets have been provided with a vertically accessable top opening channel for insertion and removal of the arch wire. Examples of such constructions are shown in U.S. Pat. Nos. 1,280,628; 1,821,171; and 3,435,527. However, most of these brackets are intended for use on the exterior surface of the tooth.
The construction of U.S. Pat. No. 4,171,568 is believed to be the closest prior art to my invention since it shows the use of a locking element for maintaining the arch wire in a secured position within a channel formed in the bracket. However, the channel is a horizontally opening channel designed for use on the labial (outside the tooth surface) and not a vertical opening channel which greatly facilitates the installation and removal of the arch wire on the lingual. Also, the locking pin of this prior bracket construction is not removable and should it become damaged during its period of use it would require replacement of the entire bracket which is time consuming and especially difficult on the linqual for the dentist and discomforting for the patient.
The bracket construction of U.S. Pat. No. 4,268,249 discloses a top opening vertical channel for receiving an arch wire in combination with a locking element. However, the bracket of this patent requires a separate insert which forms the base of the channel and requires a special tool for locking the arch wire retainer in position. Also, the locking retainer is not replaceable should it become damaged which would require replacement of the entire bracket. Also, an individual orthodontis could not fabricate a rectangular torquing arch wire in his office because of the extreme torque angle of the slot when used on the lingual.
Accordingly, the need has existed for an improved orthodontic bracket which has a vertically opening channel for receivably mounting an arch wire therein together with removable locking means for securing the arch wire in position.